The 17-year-old Bell 407 helicopter operated by Aerotrans Services Pvt Ltd, with six passengers onboard, crashed 24 minutes after being airborne on May 8.
New Delhi: A preliminary probe into the helicopter crash that killed six people in Uttarakhand in May has found that the main rotor blade of the chopper struck an overhead fibre cable, before tumbling down the hillside and coming to rest against a tree.
The Aircraft Accident Investigation Bureau (AAIB) said on Saturday that the investigation team is working on the further course of action to find the root cause of the accident.
The 17-year-old Bell 407 helicopter operated by Aerotrans Services Pvt Ltd, with six passengers onboard, crashed 24 minutes after being airborne on May 8.
The Aircraft Accident Investigation Bureau (AAIB) on Saturday released the preliminary report into the May 8 Uttarkashi helicopter crash which claimed the lives of six people including the pilot.
The report said that the helicopter crash near Gangnani in Uttarkashi was caused during emergency landing by the main rotor blade striking an overhead fibre optic cable.
The report said that 20 minutes after takeoff, the helicopter began to descend from its assigned altitude.
One passenger survived but sustained serious injuries. The crash occurred around 08:35 am during a chartered Char Dham Yatra flight.
The Bell 407 helicopter, registered as VT-OXF and operated by Aerotrans Services Pvt. Ltd., had departed from Kharsali Helipad to Jhala Helipad with six passengers. This was a single-pilot operation and followed an earlier routine hill familiarisation flight completed earlier that day.
“The purpose of the flight was Charter flying for Char Dham Yatra. This was a single pilot operation flight, and this sector was planned to be operated by another pilot. The assigned flight level for this entire sector was 10,500ft AMSL… The helicopter airborne again at 08:11 IST from Kharsali helipad,” the report said.
Investigators noted that the helicopter began descending from its assigned cruising altitude and attempted an emergency landing on the Uttarkashi-Gangotri Road (NH 34), near Gangnani.
During the descent, the main rotor blade struck an overhead cable that ran parallel to the road. The impact also damaged nearby metal barricades before the helicopter tumbled down a steep slope. It eventually came to rest against a tree roughly 250 feet into a gorge.
“The helicopter flew for 20 minutes before descending from its assigned altitude… Eventually, it came to rest against a tree, approximately 250 feet deep into a gorge,” the report said.
The report said the aircraft was airworthy at the time of the flight. Records show a tail rotor defect had been fixed two days prior to the crash and is not believed to have contributed to the incident. All required inspections were current as of April 25, 2025.
“The BELL 407 helicopter was manufactured in 2008… The last scheduled inspections were carried out on April 25, 2025,” the report noted.
The technical logbook showed the last pilot-reported defect was tail rotor skin peeling on May 3, 2025, which was corrected by May 7.
“The last defect reported by the pilot was ‘surface skin peeled at the tail rotor tip’… the Certificate to Release to service was issued on 07th May 2025,” the report said.
The wreckage has been transported to a secure facility for further examination. Experts from the US National Transportation Safety Board (NTSB), Transportation Safety Board of Canada (TSB), and Rolls-Royce are aiding in the investigation.
“The investigation team visited the accident site and carried out onsite investigation… The identified helicopter and engine components were brought to the AAIB Headquarters by the investigation team,” the report said.
Additional coordination with international authorities and technical advisors is ongoing as investigators continue to gather and analyse evidence to determine the root causes.